Passenger cars and small trucks generally include a front end mounting structure which serves as the central installation platform for a frontend module of passenger cars or small trucks onto which the various individual components of the frontend module are attached in a preassembly step. Because motor vehicles of the kind included here have similar support structures, frame-shaped mounting structures are used throughout and assume air guiding and air sealing functions for the necessary radiator components. This is accomplished with the sealing rib located at the crossmember of the mounting structure and adjacent to the air cooled pass-through area surrounded by the mounting structure.
In most cases, the upper crossmember of the mounting structure is designed for receiving the hood lock of the respective motor vehicle, where a secure locking of the vehicle's front hood is essential. Even during regular driving operation, large external forces acting upon the hood must be introduced into the crossmember of the mounting structure from where they are diverted via the mounting structure into the support structure of the motor vehicle. In this process, only very small elastic deformations may occur in the upper crossmember of the mounting structure, which must be dimensioned sufficiently with regard to stiffness and strength.
Under extreme loads at a crash situation of the vehicle, even greater forces must be absorbed by the mounting structure via the hood lock, which for safety reasons must not lead to a breakaway hood lock from the mounting structure.
Accordingly, the upper crossmember of the mounting structure, which serves as the lock crossmember, must be provided with a moment of inertia. This applies regardless of whether the upper crossmember is designed as a purely synthetic component or as a hybrid component made of a metal-synthetics composite. The problem in this situation is that a sufficient stiffness of the crossmember with simultaneously desired weight reduction can be achieved only through a greater construction height in the main load direction. Especially in cases where a center brace for supporting the upper crossmember at the lower crossmember is to be avoided, the resultant construction height of the crossmember even with favorable profile shapes is such that it leads to covering of the upper parts of the radiator components and in so doing reduces the theoretically possible heat transfer surface.